I think that like how I personally used to get it mixed up was that being from neither of the two countries the swi or swe part of the names sounded so similar that when I was younger I would mix it up. And when not thinking clearly I don't always process what place I am talking about so that may be where others have the mix up as well but yeah.

As an Estonian, I'm not sure if to feel proud that someone actually knew that my country existed, or be sad because it was confused with Sweden... But then again, Sweden is such an awesome country, it might be a good thing that the two were confused x.x